DIY Serum Formulation for Acne, Brightening, and Hydration

Hello,

Thank you for your question about your DIY essence formulation. It's great that you're trying to create a product tailored to your skin concerns (hydration, brightening, dark spots, acne for combination skin with acne and scars).

Based on the ingredients you proposed and the feedback from our staff, there are a couple of points to consider:

1. Centella Asiatica Extract: This ingredient needs to be dissolved in oil and cannot be dissolved directly in water. Your formula would require an oil phase and an emulsifier to incorporate it properly.
2. Vitamin C (L-ascorbic acid): L-ascorbic acid is highly unstable in water-based formulas and degrades quickly. It requires specific formulation techniques, often involving low pH or anhydrous bases, to remain stable and effective.

Our staff has provided a revised formula suggestion that addresses these points and targets your skin concerns:

Recommended Revised Formula:

Water Phase:

• Double Hyaluron Liquid: 2% (For hydration)
• Salicylic Acid EZ: 5% (Helps with acne and exfoliation)
• Licorice Extract: 1% (Helps balance oil and reduce redness)
• Zinc PCA: 1% (Helps balance oil, speed up acne healing, and wound recovery)
• Safe-B3 (Niacinamide): 5% (Helps balance oil, reduce acne occurrence, and brighten skin)

Oil Phase:

• Centella Asiatica Extract (Madecassoside 7.7%): 1% (Needs to be dissolved in oil)

Emulsifier & Thickener:

• Pro Polymer: 1% (To combine the water and oil phases and create the desired texture)

Water: qs. to 100%

Regarding your specific questions:

• Vit C vs Salicylic Acid: The revised formula includes Salicylic Acid EZ and other ingredients like Safe-B3 and Licorice Extract to address brightening and acne concerns, which are more suitable for this type of water-based emulsion compared to L-ascorbic acid.
• Preservative: Double Hyaluron Liquid contains preservatives. While the staff's suggested formula doesn't add an extra preservative, ensuring adequate preservation for the final product's intended shelf life is generally important in DIY formulations.
• Order of adding Centella and Vit C: Since L-ascorbic acid is not included in the revised formula, the specific order for those two is not applicable. In the revised formula, you would prepare the water phase and oil phase separately and then combine them using the emulsifier (Pro Polymer).
• pH adjustment for Vit C: This is not necessary as L-ascorbic acid is not used. The final pH of the revised formula should be checked to ensure it is suitable for the ingredients (like Salicylic Acid and Safe-B3) and skin.

We hope this revised formula suggestion is helpful for your first DIY project!